There are Localized type transmission and Distributed type transmission as a transmission method in a downlink data channel.
As shown in FIG. 1A, in the Localized type transmission, each user is assigned a frequency block as a unit. For example, in the Localized type transmission, a frequency block in which frequency selectivity fading is good is assigned. Generally, the Localized type transmission is a transmission method that is effective when a transmission data size is large and frequency scheduling effect is aimed.
As shown in FIG. 1B, in the Distributed type transmission, data is transmitted by distributing the data over the whole of an assigned band irrespective of frequency blocks. For example, the Distributed type transmission is used in a state in which frequency scheduling cannot be performed due to high-speed movement, and is used when transmission data is small such as VoIP. Generally, the Distributed type transmission is a transmission method effective when transmission data size is small and frequency diversity effect is aimed.